How to Make Bamboo Rain Gutters
Bamboo rain gutters are a green alternative to metal and plastic gutters and are mostly used in areas where bamboo is abundantly available. Bamboo gutters are cheaper and provide a beautiful rustic appeal, but are less durable than conventional gutters.
However, they are perfectly suited to harvest rainwater from a roof and irrigate a small vegetable garden for example. Rainwater can be easily harvested when it flows through an outlet drain that is connected by a pipe to a rainwater tank or container.
The usual form of a bamboo gutter for conveying water from a roof consists of a large diameter bamboo split lengthwise, with all the nodes removed. This is held to eaves by iron hooks, or by long pieces of wood or tree wigs nailed to the rafters, and notched in the upper edges to rest the split bamboo.
Sizes of Bamboo Rain Gutters and Outlet Drains
The size of the rainwater gutter is determined by the roof area and slope, while the diameter of the outlet drain is proportional to the roof area and the width of the gutter. In the table below you are able to calculate the appropriate gutter width and outlet drain diameter corresponding to a roof area:
| Roof Area (m²) | Gutter Width (cm) | Diameter Outlet Drain (cm) |
|---|---|---|
| 50 | 12 | 6.5 |
| 60 | 13 | 6.5 |
| 70 | 14 | 6.5 |
| 80 | 15 | 7.5 |
| 90 | 16 | 7.5 |
| 100 | 17 | 7.5 |
The depth of the bamboo gutter is approximately one-half of the gutter width. For example, if the gutter is 13 centimeters wide, then the depth should be 6.5 cm.
The diameter of the outlet drain is proportional to the volume of rainwater collected in the gutter. Otherwise, rainwater could overflow if the outlet drain were too small.
Installing a Bamboo Rain Gutter to a Roof Structure
Measure the length of the roof where you are about to install the bamboo gutter. Stretch a tape measure all the way to the opposite end of the wall to determine the proper length for the bamboo gutter.
Lay the split bamboo on a flat surface and measure to where it needs to be cut. Draw a pencil line all the way around the exterior of the bamboo gutter.
Wrap a piece of masking tape around the bamboo where it needs to be cut to prevent splitting or splintering of the bamboo.
Cut the bamboo with a fine-tooth hand or table saw.
After it is cut to size, remove the masking tape from the bamboo gutter.
Fix the bamboo gutter to the roof.
Fixing the Bamboo Gutter to a Roof Structure
There are different ways of fixing bamboo rain gutters to a roof structure, the following illustrations show the most common examples:
1. Fix the bamboo gutter to a bamboo roof structure using cross-fixed wooden gutter holders.
2. Fix the bamboo gutter to a wooden roof structure using cross-fixed wooden gutter holders.
3. Fix the bamboo gutter to a wooden roof structure using wooden eaves.
4. Fix the bamboo gutter with iron gutter holders to a wooden roof structure using wooden eaves.
5a. Using tree twigs as gutter holders.
5b. Fix the tree twig gutter holders to the roof structure with rope, iron wire or nails.
Rainwater Harvesting with Bamboo Gutters
Bamboo rain gutter grow system with 14 pots of vegetables.
Source: UNICEF
What kind of treatment would you recommend for rain gutters made from bamboo? Let’s assume you want to collect that rain water for your crops, so no toxic chemicals. For this application, is doing nothing equivalent to using boric acid borax?